SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '359703cf6fc9f883e24ec257aae3612d97dd0c0c799cde6b753783369e69098b' 
  AND token = 'WuXWFuPoEOQ254008/6VNKZjmcnQfUGCjq9L4vySIns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}